The Utilisation of Electrical Resistivity Imaging (ERI) for Geological Structures Mapping in Rock Mass: A Review

Electrical Resistivity Imaging (ERI) is an in-situ geophysical method widely used in environmental, engineering and hydrogeological explorations due to cost, time, and data coverage efficiency. Traditionally, geotechnical parameters such as discontinuities properties are obtained from rock samples acquired from a borehole. However, it only provides a single information point, costly and time-consuming. Thus, an approach using electrical resistivity to detect the presence of geological structure in a rock mass is an alternative method that can be applied. Discontinuities in rock mass include joints, bedding planes, blasting cracks, fractures, faults, and folds. This paper aims to present the utilisation of geoelectrical resistivity imaging for geological structures mapping in rock mass based on the review from previous research. The Electrical Resistivity Imaging (ERI) method is an effective tool to obtain structural differentiation of geological medium by interpreting 2D and even 3D electrical resistivity models. Electrical Resistivity Imaging (ERI) is an automated data acquisition system, inversion codes, non-invasive and user-friendly. The raw data received from data acquisition was analysed using Res2DINV software. The data inversion was done by applying the robust method and finite element grid to accommodate the steep topography. The data interpretation included numerical modelling to assess the suitability of all used electrode arrays in relation to the geological setting.